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/*
* Copyright (C) 2013-2022 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "ClassInfo.h"
#include "JSCast.h"
#include "JSTypeInfo.h"
#include "PropertyOffset.h"
#include "PropertySlot.h"
#include <wtf/FixedVector.h>
namespace JSC {
class JSPropertyNameEnumerator;
class LLIntOffsetsExtractor;
class Structure;
class StructureChain;
class CachedSpecialPropertyAdaptiveStructureWatchpoint;
class CachedSpecialPropertyAdaptiveInferredPropertyValueWatchpoint;
struct SpecialPropertyCache;
enum class CachedPropertyNamesKind : uint8_t {
EnumerableStrings = 0,
Strings,
Symbols,
StringsAndSymbols,
};
static constexpr unsigned numberOfCachedPropertyNames = 4;
enum class CachedSpecialPropertyKey : uint8_t {
ToStringTag = 0,
ToString,
ValueOf,
ToPrimitive,
ToJSON,
};
static constexpr unsigned numberOfCachedSpecialPropertyKeys = 5;
class StructureRareData;
class StructureChainInvalidationWatchpoint;
class StructureRareData final : public JSCell {
public:
typedef JSCell Base;
static constexpr unsigned StructureFlags = Base::StructureFlags | StructureIsImmortal;
template<typename CellType, SubspaceAccess>
static GCClient::IsoSubspace* subspaceFor(VM& vm)
{
return &vm.structureRareDataSpace();
}
static StructureRareData* create(VM&, Structure*);
static constexpr DestructionMode needsDestruction = NeedsDestruction;
static void destroy(JSCell*);
DECLARE_VISIT_CHILDREN;
static Structure* createStructure(VM&, JSGlobalObject*, JSValue prototype);
Structure* previousID() const
{
return m_previous.get();
}
void setPreviousID(VM&, Structure*);
void clearPreviousID();
JSValue cachedSpecialProperty(CachedSpecialPropertyKey) const;
void cacheSpecialProperty(JSGlobalObject*, VM&, Structure* baseStructure, JSValue, CachedSpecialPropertyKey, const PropertySlot&);
JSPropertyNameEnumerator* cachedPropertyNameEnumerator() const;
uintptr_t cachedPropertyNameEnumeratorAndFlag() const;
void setCachedPropertyNameEnumerator(VM&, Structure*, JSPropertyNameEnumerator*, StructureChain*);
void clearCachedPropertyNameEnumerator();
JSImmutableButterfly* cachedPropertyNames(CachedPropertyNamesKind) const;
JSImmutableButterfly* cachedPropertyNamesIgnoringSentinel(CachedPropertyNamesKind) const;
JSImmutableButterfly* cachedPropertyNamesConcurrently(CachedPropertyNamesKind) const;
void setCachedPropertyNames(VM&, CachedPropertyNamesKind, JSImmutableButterfly*);
Box<InlineWatchpointSet> copySharedPolyProtoWatchpoint() const { return m_polyProtoWatchpoint; }
const Box<InlineWatchpointSet>& sharedPolyProtoWatchpoint() const { return m_polyProtoWatchpoint; }
void setSharedPolyProtoWatchpoint(Box<InlineWatchpointSet>&& sharedPolyProtoWatchpoint) { m_polyProtoWatchpoint = WTFMove(sharedPolyProtoWatchpoint); }
bool hasSharedPolyProtoWatchpoint() const { return static_cast<bool>(m_polyProtoWatchpoint); }
static JSImmutableButterfly* cachedPropertyNamesSentinel() { return std::bit_cast<JSImmutableButterfly*>(static_cast<uintptr_t>(1)); }
static constexpr ptrdiff_t offsetOfCachedPropertyNames(CachedPropertyNamesKind kind)
{
return OBJECT_OFFSETOF(StructureRareData, m_cachedPropertyNames) + sizeof(WriteBarrier<JSImmutableButterfly>) * static_cast<unsigned>(kind);
}
static constexpr ptrdiff_t offsetOfCachedPropertyNameEnumeratorAndFlag()
{
return OBJECT_OFFSETOF(StructureRareData, m_cachedPropertyNameEnumeratorAndFlag);
}
static constexpr ptrdiff_t offsetOfSpecialPropertyCache()
{
return OBJECT_OFFSETOF(StructureRareData, m_specialPropertyCache);
}
static constexpr ptrdiff_t offsetOfPrevious()
{
return OBJECT_OFFSETOF(StructureRareData, m_previous);
}
DECLARE_EXPORT_INFO;
void finalizeUnconditionally(VM&, CollectionScope);
static constexpr uintptr_t cachedPropertyNameEnumeratorIsValidatedViaTraversingFlag = 1;
static constexpr uintptr_t cachedPropertyNameEnumeratorMask = ~static_cast<uintptr_t>(1);
unsigned incrementActiveReplacementWatchpointSet()
{
return ++m_activeReplacementWatchpointSet;
}
unsigned decrementActiveReplacementWatchpointSet()
{
return --m_activeReplacementWatchpointSet;
}
private:
friend class LLIntOffsetsExtractor;
friend class Structure;
friend class CachedSpecialPropertyAdaptiveStructureWatchpoint;
friend class CachedSpecialPropertyAdaptiveInferredPropertyValueWatchpoint;
StructureRareData(VM&, Structure*);
void clearCachedSpecialProperty(CachedSpecialPropertyKey);
void cacheSpecialPropertySlow(JSGlobalObject*, VM&, Structure* baseStructure, JSValue, CachedSpecialPropertyKey, const PropertySlot&);
SpecialPropertyCache& ensureSpecialPropertyCache();
SpecialPropertyCache& ensureSpecialPropertyCacheSlow();
bool canCacheSpecialProperty(CachedSpecialPropertyKey);
void giveUpOnSpecialPropertyCache(CachedSpecialPropertyKey);
bool tryCachePropertyNameEnumeratorViaWatchpoint(VM&, Structure*, StructureChain*);
// FIXME: We should have some story for clearing these property names caches in GC.
// https://bugs.webkit.org/show_bug.cgi?id=192659
uintptr_t m_cachedPropertyNameEnumeratorAndFlag { 0 };
FixedVector<StructureChainInvalidationWatchpoint> m_cachedPropertyNameEnumeratorWatchpoints;
WriteBarrier<JSImmutableButterfly> m_cachedPropertyNames[numberOfCachedPropertyNames] { };
typedef UncheckedKeyHashMap<PropertyOffset, RefPtr<WatchpointSet>, WTF::IntHash<PropertyOffset>, WTF::UnsignedWithZeroKeyHashTraits<PropertyOffset>> PropertyWatchpointMap;
#ifdef NDEBUG
static_assert(sizeof(PropertyWatchpointMap) == sizeof(void*), "StructureRareData should remain small");
#endif
PropertyWatchpointMap m_replacementWatchpointSets;
std::unique_ptr<SpecialPropertyCache> m_specialPropertyCache;
Box<InlineWatchpointSet> m_polyProtoWatchpoint;
WriteBarrierStructureID m_previous;
PropertyOffset m_maxOffset;
PropertyOffset m_transitionOffset;
unsigned m_activeReplacementWatchpointSet { 0 };
};
} // namespace JSC
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